Dental tool



(No Model.) A. M. HARRISON.

DENTAL TUOI..v

No. 474,011. 'Patented May 3,1892.

UNITED STATES PATENT OEEIcE.Y

ALMER M. HARRISON,

OF COLUMBUS, OHIO.

DENTAL TOOL.

SPECIFICATION forming part of Letters Patent N 0. 474,011, dated May 3, 1892.

Application filed August 28, 1891.

T0 all whom it may concern: Y

Be it known that I, ALMER M. HARRISON, a citizen ofthe United States, residing at Col umbus, in the county of Franklin and State of Ohio, have invented a certain new and useful Improvement in Dental Tools, of which the following is a specification.

Myinvention relates to the improvement of dental tools, and has particular relation to that class of tools which are supported and rotated b y a suitable dental machine.

The objects of myinvention are to provide an improved tool of this class particularly adapted for trimming or gradually cutting away the roots or other parts of a tooth, to so construct said tool as to admit of the cuttingblade being readily and easily detached from its support for the purpose of sharpening or substitution of blades having differentlyformed cutting-surfaces, and to produce said tool in a neat, simple, and inexpensive form and of a reliable and durable construct-ion. These'objects I accomplish in the same manner illustrated in the accompanying drawings, in which- Figure l is a View in elevation of my improved tool. Fig. 2 is a central vertical section of the same; and Fig. 3 is an enlarged detail view in elevation of the outer portion of the tool, the point of view being at right angles with that shown in Fig. l.

Similarletters refer to similar parts throughout the several views.

a represents the usual spindle-shaped shank, one end of which is adapted to be connected and supported by,iu the usual or desired manner, the hand-piece of a dental machine. In or to the outer end of the shank c I cause to be rigidly connected one end of a screwthreaded extension h, upon which may be formed either right or left hand threads. The outer portion of this screw extension b terminates in a short pin or pivot-shaped projection or extension c,which is formed within the center of said screw, and is, as shown, of a less diameter than the body of the latter, resulting in the formation about'the base of said pin extension of a circular shoulder c. Formed in the center of the screw portion b and eX- tending from a point from the lower portion thereof to a point in the base of the pin eX- tension c is a longitudinal mortise or open slot Serial No. 403,972. (No model.)

d, which is of a width adapted to receive or admit of the insertion therein of the desired thickness of cutting-blade. Upon the screw o is mounted a suitable form of internallythreaded thumb-nut e, the threads of which are adapted to engage with the external threads of said screw, as indicated in the drawings. Loosely surrounding the screw and resting upon the outer end of the thumb-nut e is a metallic washerf, which is of a greater circumference than said thumb-nut and which is provided on its outer face with a bladere ceiving channel or groove g, which extends diametrically across said washer.

t' represents the cutting-blade, which, as shown, is inserted within the outer portion of the mortise d, and the horizont-al base edge of which is adapted to bear against the outer face of the washer f and within the groove g of the latter. The blade 'i is held firmly in its position in the mortise by turning outwardly the thu m b-nut c until the pressure of the outer end of the latter results in clamping the longer edges of the blade t' between the outer end of the mortise d and the outer face of the washer f. As indicated at k, the outer end of the blade t' is sharpened in the manner desired on opposite sides of the pin c, thus resulting in a cutting-edge on said blade, which is at right angles with the axis of the tool stem or body. In practice the tool-shank c is connected in the usual manner with the hand-piece of the tool-rotating machine, the pin c inserted in a previously-formed socketof the tooth until the cutting-edge of the blade is in contact with the surface of the tooth, and the rotating motion imparted to the tool in the usual manner. By this rotation of the tool it is obvious that the cutting-edge of the blade will serve to gradually cut away the surface of the tooth with which it is in contact, said cutting action being uniform and complete at each point of Contact.

It is obvious that I may substitute for the straight cutting-blade shown at t' a blade having other forms or contours of cutting-edges without departing from the spirit of my invention.

It will readily be seen that bythe construction described the blade may be readily released and removed from its holder by turn- ICC ing inward the thumb-nut and drawing said blade vfrom the mortse. In this manner it will be seen that not only may the blade be removed for the purpose of sharpening or repairing, but that new blades having different forms of cutting-edges may be substituted When desired. It Will also be seen that the construction herein shown and described is neat and reliable and is Without'complication.

Having now fully described my invention, what I claim, and desire to secure by Letters Patent, is-

l. In a dental tool, the combination of the shank a, the n iortise d, and screw-threaded extension b, connected therewith, With a cutting-blade i, inserted Within said lnortise, and a thumb-nut e on its screw-threaded extension, said thumb-nut adapted to clamp said ALMER M. HARRISON.

In presence of- I-IENRY A. WILLIAMS, C. C. SHEPHERD. 

